1. Field of the Invention
The present invention relates to a curable composition capable of forming a cured coating film excellent in abrasion resistance, transparency, anti-fouling property and non-tackiness (release property), a cured coating film formed by such a curable composition and a coated substrate having such a cured coating film.
2. Discussion of Background
A protective film to be formed on the surface of a substrate such as a lens, a display or a photomask, is required have a hard coat property, an anti-fouling property, non-tackiness, etc.
However, heretofore, it used to be required to carry out a hard coat processing to form a hard coating film and an anti-fouling non-tackiness processing to form a coating film having a low surface tension property such as water repellency or oil repellency, separately, in order to form a protective film having the above-mentioned plurality of properties on the surface of a substrate. Accordingly, separate steps are required, thus leading to an increase of costs.
In order to reduce the costs, various attempts have been proposed to form a coating film satisfying the above-mentioned plurality of properties, in a single step. For example, JP-A-10-104403 discloses a sheet having a cured film made of an ultraviolet curable resin and an oligomer containing a fluorine atom-containing alkylalkoxysilane; JP-A-6-211945 discloses a sheet having a cured film made of an alkyl fluoroacrylate and an acrylate not-compatible with an alkyl fluoroacrylate; and JP-A-11-305420 discloses a protective layer for a photomask having a release property from a resist improved.
However, in the case of JP-A-10-104403, the reactivity between the ultraviolet curable resin and the fluorine atom-containing oligomer is poor, whereby there was a problem that the fluorine atom-containing oligomer tends to bleed out as time passes. In the case of JP-A-6-211945, the compatibility of the two materials is poor, whereby there was a problem that a uniform coating film can not be obtained, and it is difficult to obtain a coating film having transparency and good appearance. And, in the case of JP-A-11-305420, a heat curing step is required, whereby there was a problem that the productivity is low.
It is an object of the present invention to provide a curable composition capable of forming, in a single coating step, a cured coating film which has an anti-fouling property and a release property and is excellent in abrasion resistance, whereby such properties will not be deteriorated even when used for a long period of time, a cured coating film formed by such a curable composition, and a coated substrate having such a cured coating film.
The present invention provides a curable composition comprising a compound (A) having at least one active energy ray curable polymerizable functional group, a fluorine-containing copolymer (B) obtained by (1) copolymerizing a polymerizable monomer (a) having a polyfluoroalkyl group and a polymerizable monomer (b) having a photo-curable functional group, or (2) introducing a photo-curable functional group into a fluorine-containing copolymer (D) obtained by copolymerizing a polymerizable monomer (a) having a polyfluoroalkyl group and a polymerizable monomer (d) having a group capable of introducing a photo-curable functional group, and a photopolymerization initiator (C).
In the present invention, the curable composition preferably contains from 0.01 to 20 parts by mass of the fluorine-containing copolymer (B) and from 0.01 to 20 parts by mass of the photopolymerization initiator (C), per 100 parts by mass of the compound (A).
Further, the present invention provides a cured coating film formed by the above curable composition.
Still further, the present invention provides a coated substrate comprising a substrate and such a cured coating film formed on at least one side of the substrate. In this invention, the substrate is preferably a photomask.
According to the present invention, it is possible to provide a curable composition capable of forming, in a single coating step, a cured coating film which has an anti-fouling property and a release property and is excellent in abrasion resistance, whereby such properties will not deteriorate even when used for a long period of time, a cured coating film having the above-mentioned properties, formed by such a curable composition, and a coated substrate having such a cured coating film.